How many supernovas have been spectrally analyzed out of the total? How many stars placed on the Hartzsprung-Russel diagram of the the total number of stars? How many orbits have been observed, calculated and prdicted to verify the law of gravity out however many orbits there are?
Different diciplines, different planets. Ya think? As if, having not explored a tiny percent of our own planet, we know all about the others.